Figure 4.

Phenotypes of transgenic rice plants overexpressing OsYUCCA1. A, Schematic representation of the pAct-OsYUCCA1 construct. The full-length OsYUCCA1 cDNA is expressed under the control of the rice actin1 promoter. B and C, Typical phenotypes of transgenic calli 2 weeks after regeneration. Bar = 5 mm. Callus produced crown roots with abundant hairy roots (B) and often also produced several leaflets (C). D, Aberrant morphology of leaflet protruded from transgenic callus. Bar = 4 mm. Vascular tissues often stopped at the leaf margin (superimposed photo at top right). E, Gross morphology of regenerated plants carrying the control vector (left) or pAct-OsYUCCA1 with mild phenotype (right) at 3 weeks after regeneration. The pAct-OsYUCCA1 plant is enlarged at top right. F, Abnormal elongation of internode and ectopic development of crown roots from elongated node in pAct-OsYUCCA1 plants. Bar = 5 mm. G, Longitudinal section of the elongated internode of F. Bar = 5 mm. H and I, Root morphology of control (H) and pAct-OsYUCCA1 (I) plants. Roots of pAct-OsYUCCA1 plants were often thicker than those of the control plants and grew in random directions (indicated by arrows). Bar = 5 mm.